/*样式一*/
;(function ($) {
  $.fn.snow = function (options) {
    var $flake = $('<div id="snowbox" />').css({ position: 'absolute', 'z-index': '9999', top: '-50px' }).html('&#10052;'),
      documentHeight = $(document).height(),
      documentWidth = $(document).width(),
      defaults = {
        minSize: 10,
        maxSize: 20,
        newOn: 1000,
        flakeColor: '#AFDAEF' /* 此处可以定义雪花颜色，若要白色可以改为#FFFFFF */
      },
      options = $.extend({}, defaults, options)
    var interval = setInterval(function () {
      var startPositionLeft = Math.random() * documentWidth - 100,
        startOpacity = 0.5 + Math.random(),
        sizeFlake = options.minSize + Math.random() * options.maxSize,
        endPositionTop = documentHeight - 200,
        endPositionLeft = startPositionLeft - 500 + Math.random() * 500,
        durationFall = documentHeight * 10 + Math.random() * 5000
      $flake
        .clone()
        .appendTo('body')
        .css({
          left: startPositionLeft,
          opacity: startOpacity,
          'font-size': sizeFlake,
          color: options.flakeColor
        })
        .animate(
          {
            top: endPositionTop,
            left: endPositionLeft,
            opacity: 0.2
          },
          durationFall,
          'linear',
          function () {
            $(this).remove()
          }
        )
    }, options.newOn)
  }
})(jQuery)
$(function () {
  $.fn.snow({
    minSize: 5 /* 定义雪花最小尺寸 */,
    maxSize: 50 /* 定义雪花最大尺寸 */,
    newOn: 300 /* 定义密集程度，数字越小越密集 */
  })
})
